Roche’s HER2 (4B5) Diagnostic Expansion: A Game-Changer in Precision Oncology and Therapeutic Access

Roche’s recent advancements in HER2 diagnostics, particularly the CE IVDR approval of its VENTANA HER2 (4B5) test for identifying HER2-ultralow metastatic breast cancer and HER2-positive biliary tract cancer (BTC) patients, mark a pivotal moment in precision oncology. By expanding access to targeted therapies like ENHERTU (trastuzumab deruxtecan) and ZIIHERA (zanidatamab-hrii), Roche is not only redefining patient stratification but also solidifying its leadership in a rapidly growing market. For investors, this expansion underscores Roche’s ability to leverage regulatory milestones and strategic collaborations to unlock new revenue streams while addressing unmet medical needs.

Regulatory Breakthroughs and Market Expansion

In 2025, Roche secured CE IVDR approval for its VENTANA HER2 (4B5) test to identify two critical patient populations: HR-positive, HER2-ultralow metastatic breast cancer patients eligible for ENHERTU and HER2-positive BTC patients eligible for ZIIHERA [1]. This approval positions Roche as the first and only provider of a companion diagnostic for HER2-ultralow status, a classification that emerged in 2022 and now accounts for 20–25% of HR-positive, HER2-negative breast cancer cases [2]. By capturing this underserved cohort, Roche’s test directly aligns with the therapeutic pipeline of ENHERTU, which demonstrated a 36% reduction in disease progression or death in the DESTINY-Breast06 trial compared to chemotherapy [3].

The BTC application further diversifies Roche’s oncology footprint. Biliary tract cancer, though less common, is an aggressive disease with limited treatment options. Roche’s diagnostic now enables Jazz Pharmaceuticals’ ZIIHERA to target HER2-positive BTC patients, a population previously excluded from HER2-directed therapies [1]. These approvals, combined with the test’s FDA clearance in the U.S., create a dual-market advantage, ensuring Roche’s diagnostics remain integral to both European and global therapeutic pathways.

Strategic Collaborations and Therapeutic Synergies

Roche’s success hinges on its long-term partnerships with biopharma leaders. The collaboration with Daiichi Sankyo, initiated in 2018, exemplifies this synergy. By co-developing the HER2-low companion diagnostic for ENHERTU, Roche ensured its test would be embedded in the drug’s clinical trials and commercialization strategy [6]. This alignment guarantees that Roche’s diagnostics remain a gatekeeper for ENHERTU, which is projected to become a blockbuster in metastatic breast cancer. Similarly, the partnership with Jazz Pharmaceuticals for BTC expands Roche’s reach into niche oncology markets, where HER2-positive subsets are increasingly targeted with antibody-drug conjugates (ADCs) [1].

These collaborations are not merely transactional; they reflect Roche’s strategic foresight in aligning diagnostic innovation with therapeutic advancements. By co-developing tests alongside drug pipelines, Roche secures a first-mover advantage in emerging indications, reducing the risk of market fragmentation and ensuring its diagnostics remain indispensable to treatment protocols.

Market Dynamics and Financial Implications

The companion diagnostics market is forecasted to grow at a 12.42% CAGR, reaching USD 15.62 billion by 2030, driven by precision medicine adoption and liquid biopsy innovations [4]. Roche’s HER2 (4B5) test is uniquely positioned to capitalize on this growth. In 2025, the HER2 testing market was valued at USD 166.34 million, with breast cancer accounting for 40% of the share [4]. Roche’s dominance in this segment—bolstered by its FDA- and CE-approved tests—suggests a strong revenue contribution from the Diagnostics Division, which reported CHF 3,491 million in Q1 2025 sales [5].

While specific revenue figures for the HER2 (4B5) test are not disclosed, its integration into pivotal trials and therapeutic pathways implies a direct correlation with ENHERTU and ZIIHERA sales. As these drugs scale, Roche’s diagnostics will see parallel growth, particularly in Europe, where CE IVDR compliance is now a regulatory requirement for in vitro diagnostic devices. This regulatory tailwind ensures rapid adoption of Roche’s test in CE IVDR-compliant markets, further entrenching its market leadership.

Long-Term Investment Potential

For investors, Roche’s HER2 (4B5) expansion represents a dual opportunity: a defensible market position in a high-growth sector and a scalable platform for future innovations. The company’s leadership in HER2 diagnostics—spanning immunoassays, molecular tests, and digital solutions—positions it to benefit from the broader shift toward personalized medicine [5]. Additionally, Roche’s focus on low- and middle-income countries, where late-stage cancer diagnoses are prevalent, opens avenues for long-term revenue diversification [5].

However, risks remain. The companion diagnostics market is competitive, with rivals like Ventana Medical Systems (a subsidiary of Roche) and emerging players in liquid biopsy technologies. Yet, Roche’s first-mover advantage in HER2-ultralow diagnostics, coupled with its deep partnerships, creates a high barrier to entry.

Conclusion

Roche’s HER2 (4B5) diagnostic expansion is more than a regulatory win—it is a strategic masterstroke in precision oncology. By securing CE IVDR approvals, aligning with blockbuster therapeutics, and expanding into niche cancers like BTC, Roche has positioned itself at the forefront of a market poised for exponential growth. For investors, this represents a compelling case for long-term value creation, driven by innovation, regulatory agility, and therapeutic collaboration.

Source:
[1] Roche Receives CE IVDR Approval For HER2 (4B5) Companion Diagnostic Test To Identify HER2-Ultralow Breast Cancer And Biliary Tract Cancer Patients [https://www.barchart.com/story/news/34615572/roche-receives-ce-ivdr-approval-for-her2-4b5-companion-diagnostic-test-to-identify-her2-ultralow-breast-cancer-and-biliary-tract-cancer-patients]
[2] Roche receives FDA approval for the first companion diagnostic to identify patients with HER2-ultralow metastatic breast cancer eligible for ENHERTU [https://www.roche.com/media/releases/med-cor-2025-01-31]
[3] Analytical and clinical validation of PATHWAY HER2 (4B5) Assay for assessment of HER2-low/HER2-ultralow status and eligibility for trastuzumab deruxtecan in DESTINY-Breast06 [https://pmc.ncbi.nlm.nih.gov/articles/PMC12180978/]
[4] Companion Diagnostics Market Size and Share [https://www.mordorintelligence.com/industry-reports/companion-diagnostics-market]
[5] Untitled [https://tools.morningstar.ch/ch/stockreport/newsItem.aspx?id=TDJNDN_20250424236]
[6] Daiichi Sankyo and Roche to Collaborate on New HER2 Low Companion Diagnostic Test [https://www.daiichisankyo.com/media/press_release/detail/index_3223.html]